Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

Pediatric Malaria Workup

  • Author: Parang N Mehta, MD; Chief Editor: Russell W Steele, MD  more...
 
Updated: Sep 27, 2015
 

Approach Considerations

Demonstration of the parasite in a smear of the blood definitely establishes the presence of malaria. A negative finding on examination does not rule out malaria. Only 50% of children with malaria have positive smear findings, even on repeated examination.

Asymptomatic parasitemia is common in children from an endemic area who have partial immunity to the disease. A positive smear for malaria parasite does not always confirm a diagnosis of malaria in these children. More importantly, a positive smear should not stop the diagnostic effort in a febrile illness.

Lumbar puncture is indicated to rule out meningitis in cerebral malaria and febrile seizures with malaria. Severe P falciparum malaria is often associated with hypoglycemia. Lower blood glucose levels are associated with higher mortality rates.

Next

Other Tests

Serologic tests provide confirmation of past malaria in patients and are valuable for epidemiologic studies. These tests are also useful for screening donated blood and diagnosing hyperactive malarial splenomegaly. Among the tests used are:

  • Indirect fluorescent antibody test (IFAT)
  • Indirect hemagglutination antibody (IHA) test
  • Enzyme-linked immunosorbent assay (ELISA)
  • Immuno-chromatographic test (ICT) for filariasis

All of these tests produce positive results several days after malarial parasites appear in the blood and so do not help in the diagnosis of the acute infection for treatment purposes.

Dipstick tests based on the detection of P falciparum histidine-rich protein-2 (PfHRP-2) antigen are specific for P falciparum infections and do not detect the other 3 species. Dipstick tests based on the detection of parasite lactate dehydrogenase are now available; these tests can detect P falciparum and P vivax. These tests have high sensitivity and specificity, require no special equipment or training, and produce results rapidly. They offer an advantage where the disease is uncommon and blood smear examination expertise is not readily available. However, they remain positive for a week or more after the treatment and cure and, in this situation, can yield false-positive results.

Deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) probes and polymerase chain reaction (PCR) assays have good sensitivity and specificity but require sophisticated expensive equipment.

Previous
Next

Blood Smear Examination

Both thick and thin films are essential. If the parasitemia is light, a thin film examination may miss the diagnosis. Thick films save time in diagnosis of scanty infections but make species identification of the parasite difficult. At least 100-200 fields of a thick film should be scrutinized before a slide is reported as negative for malaria. In doubtful cases, the examination can be repeated after 4 hours.

Obtaining thick and thin blood films at the bedside is important. These films may have to be taken repeatedly for diagnosis. Earlobe or finger prick is used for older children; the great toe is used in infants.

Take a large drop of blood on one end of a clean slide, spread uniformly, and air-dry. A smaller drop should be spread thinly so that the end of the smear does not reach the end of the slide. Giemsa staining is suitable for identifying malarial parasites in these films.

Various techniques to enhance the diagnostic value of the peripheral blood smear examination are in use. Fluorescent staining and microscopy, centrifugation, selective magnetic separation techniques, and other techniques have been used but have only a moderate effect.

Histologic findings

The appearance of the parasite varies in the thick and thin films. The thick unfixed film shows only leucocytes and parasites; erythrocytes are destroyed in the staining process. The parasites themselves are also altered.

Young trophozoites appear as incomplete rings or spots of blue cytoplasm with discrete red nuclei. In mature trophozoites, the cytoplasm may be fragmented, and the various characteristics of the different species are often indistinct.

Gametocytes and schizonts usually retain their characteristic appearances. Thin film examination is essential for the accurate identification of plasmodial species, which has an important bearing on treatment.

Previous
 
 
Contributor Information and Disclosures
Author

Parang N Mehta, MD Consulting Staff, Department of Pediatrics, Mehta Hospital, India

Parang N Mehta, MD is a member of the following medical societies: Indian Medical Association, Indian Academy of Pediatrics

Disclosure: Nothing to disclose.

Specialty Editor Board

Mary L Windle, PharmD Adjunct Associate Professor, University of Nebraska Medical Center College of Pharmacy; Editor-in-Chief, Medscape Drug Reference

Disclosure: Nothing to disclose.

Chief Editor

Russell W Steele, MD Clinical Professor, Tulane University School of Medicine; Staff Physician, Ochsner Clinic Foundation

Russell W Steele, MD is a member of the following medical societies: American Academy of Pediatrics, American Association of Immunologists, American Pediatric Society, American Society for Microbiology, Infectious Diseases Society of America, Louisiana State Medical Society, Pediatric Infectious Diseases Society, Society for Pediatric Research, Southern Medical Association

Disclosure: Nothing to disclose.

Additional Contributors

Gary J Noel, MD Professor, Department of Pediatrics, Weill Cornell Medical College; Attending Pediatrician, New York-Presbyterian Hospital

Gary J Noel, MD is a member of the following medical societies: Pediatric Infectious Diseases Society

Disclosure: Nothing to disclose.

References
  1. World Health Organization. WHO Fact Sheet on Malaria. Fact Sheet No 94. World Health Organization. Available at http://www.who.int/mediacentre/factsheets/fs094/en/print.html. Accessed: June 29, 2007.

  2. Bhatt S, Weiss DJ, Cameron E, et al. The effect of malaria control on Plasmodium falciparum in Africa between 2000 and 2015. Nature. 2015 Sep 16. [Medline].

  3. Kelland K. Millions of Children's Lives Saved as Malaria Deaths Plunge -UN. Reuters Health Information. Available at http://www.medscape.com/viewarticle/851119. September 18, 2015; Accessed: September 28, 2015.

  4. Ezeamama AE, Spiegelman D, Hertzmark E, Bosch RJ, Manji KP, Duggan C, et al. HIV Infection and the Incidence of Malaria Among HIV-Exposed Children from Tanzania. J Infect Dis. 2012 May. 205(10):1486-94. [Medline].

  5. Idro R, Marsh K, John CC, Newton CR. Cerebral Malaria; Mechanisms Of Brain Injury And Strategies For Improved Neuro-Cognitive Outcome. Pediatr Res. 2010 Jul 2. [Medline].

  6. Scott JA, Berkley JA, Mwangi I, et al. Relation between falciparum malaria and bacteraemia in Kenyan children: a population-based, case-control study and a longitudinal study. Lancet. 2011 Oct 8. 378(9799):1316-23. [Medline].

  7. FDA Drug Safety Communication: FDA approves label changes for antimalarial drug mefloquine hydrochloride due to risk of serious psychiatric and nerve side effects. Available at http://www.fda.gov/Drugs/DrugSafety/ucm362227.htm#. Accessed: July 30, 2013.

  8. Abdulla S, Oberholzer R, Juma O, et al. Safety and immunogenicity of RTS,S/AS02D malaria vaccine in infants. N Engl J Med. 2008 Dec 11. 359(24):2533-44. [Medline].

  9. The RTS,S Clinical Trials Partnership. First results of phase 3 trial of RTS,S/AS01 malaria vaccine in African children. N Engl J Med. 2011/Oct. 365:[Full Text].

  10. White NJ. A vaccine for malaria (editorial). N Engl J Med. 2011/Oct. 365:[Full Text].

  11. Griffith KS, Lewis LS, Mali S, Parise ME. Treatment of malaria in the United States: a systematic review. JAMA. 2007 May 23. 297(20):2264-77. [Medline]. [Full Text].

  12. Sinclair D, Donegan S, Lalloo DG. Artesunate versus quinine for treating severe malaria. Cochrane Database Syst Rev. 2011 Mar 16. 3:CD005967. [Medline].

 
Previous
Next
 
The various stages of Plasmodium life cycle are shown. Knowledge of the life cycle of the malarial parasite is essential to understanding the chemotherapy of malaria.
The various stages of Plasmodium vivax as observed on Giemsa staining of a peripheral blood smear.
The various stages of Plasmodium falciparum as observed on Giemsa staining of a peripheral blood smear are shown. The presence of more than one parasite in an erythrocyte is unique to this species.
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.